config/cfgroot/ids-functions.pl

   1 #!/usr/bin/perl -w
   2 ############################################################################
   3 #                                                                          #
   4 # This file is part of the IPFire Firewall.                                #
   5 #                                                                          #
   6 # IPFire is free software; you can redistribute it and/or modify           #
   7 # it under the terms of the GNU General Public License as published by     #
   8 # the Free Software Foundation; either version 2 of the License, or        #
   9 # (at your option) any later version.                                      #
  10 #                                                                          #
  11 # IPFire is distributed in the hope that it will be useful,                #
  12 # but WITHOUT ANY WARRANTY; without even the implied warranty of           #
  13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the            #
  14 # GNU General Public License for more details.                             #
  15 #                                                                          #
  16 # You should have received a copy of the GNU General Public License        #
  17 # along with IPFire; if not, write to the Free Software                    #
  18 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA #
  19 #                                                                          #
  20 # Copyright (C) 2018-2019 IPFire Team <info@ipfire.org>                    #
  21 #                                                                          #
  22 ############################################################################
  23
  24 use strict;
  25
  26 package IDS;
  27
  28 require '/var/ipfire/general-functions.pl';
  29 require "${General::swroot}/network-functions.pl";
  30 require "${General::swroot}/suricata/ruleset-sources";
  31
  32 # Location where all config and settings files are stored.
  33 our $settingsdir = "${General::swroot}/suricata";
  34
  35 # File where the main file for providers ruleset inclusion exists.
  36 our $suricata_used_providers_file = "$settingsdir/suricata-used-providers.yaml";
  37
  38 # File for static ruleset inclusions.
  39 our $suricata_default_rulefiles_file = "$settingsdir/suricata-default-rules.yaml";
  40
  41 # File where the addresses of the homenet are stored.
  42 our $homenet_file = "$settingsdir/suricata-homenet.yaml";
  43
  44 # File where the addresses of the used DNS servers are stored.
  45 our $dns_servers_file = "$settingsdir/suricata-dns-servers.yaml";
  46
  47 # File where the HTTP ports definition is stored.
  48 our $http_ports_file = "$settingsdir/suricata-http-ports.yaml";
  49
  50 # File which contains includes for provider specific rule modifications.
  51 our $oinkmaster_provider_includes_file = "$settingsdir/oinkmaster-provider-includes.conf";
  52
  53 # File which contains wheater the rules should be changed.
  54 our $modify_sids_file = "$settingsdir/oinkmaster-modify-sids.conf";
  55
  56 # File which stores the configured IPS settings.
  57 our $ids_settings_file = "$settingsdir/settings";
  58
  59 # File which stores the used and configured ruleset providers.
  60 our $providers_settings_file = "$settingsdir/providers-settings";
  61
  62 # File which stores the configured settings for whitelisted addresses.
  63 our $ignored_file = "$settingsdir/ignored";
  64
  65 # Location where the downloaded rulesets are stored.
  66 our $dl_rules_path = "/var/tmp";
  67
  68 # File to store any errors, which also will be read and displayed by the wui.
  69 our $storederrorfile = "/tmp/ids_storederror";
  70
  71 # File to lock the WUI, while the autoupdate script runs.
  72 our $ids_page_lock_file = "/tmp/ids_page_locked";
  73
  74 # Location where the rulefiles are stored.
  75 our $rulespath = "/var/lib/suricata";
  76
  77 # Location where the default rulefils are stored.
  78 our $default_rulespath = "/usr/share/suricata/rules";
  79
  80 # Location where the addition config files are stored.
  81 our $configspath = "/usr/share/suricata";
  82
  83 # Location of the classification file.
  84 our $classification_file = "$configspath/classification.config";
  85
  86 # Location of the sid to msg mappings file.
  87 our $sid_msg_file = "$rulespath/sid-msg.map";
  88
  89 # Location to store local rules. This file will not be touched.
  90 our $local_rules_file = "$rulespath/local.rules";
  91
  92 # File which contains the rules to whitelist addresses on suricata.
  93 our $whitelist_file = "$rulespath/whitelist.rules";
  94
  95 # File which contains a list of all supported ruleset sources.
  96 # (Sourcefire, Emergingthreads, etc..)
  97 our $rulesetsourcesfile = "$settingsdir/ruleset-sources";
  98
  99 # The pidfile of the IDS.
 100 our $idspidfile = "/var/run/suricata.pid";
 101
 102 # Location of suricatactrl.
 103 my $suricatactrl = "/usr/local/bin/suricatactrl";
 104
 105 # Prefix for each downloaded ruleset.
 106 my $dl_rulesfile_prefix = "idsrules";
 107
 108 # Temporary directory where the rulesets will be extracted.
 109 my $tmp_directory = "/tmp/ids_tmp";
 110
 111 # Temporary directory where the extracted rules files will be stored.
 112 my $tmp_rules_directory = "$tmp_directory/rules";
 113
 114 # Temporary directory where the extracted additional config files will be stored.
 115 my $tmp_conf_directory = "$tmp_directory/conf";
 116
 117 # Array with allowed commands of suricatactrl.
 118 my @suricatactrl_cmds = ( 'start', 'stop', 'restart', 'reload', 'fix-rules-dir', 'cron' );
 119
 120 # Array with supported cron intervals.
 121 my @cron_intervals = ('off', 'daily', 'weekly' );
 122
 123 # Array which contains the HTTP ports, which statically will be declared as HTTP_PORTS in the
 124 # http_ports_file.
 125 my @http_ports = ('80', '81');
 126
 127 # Array which contains a list of rulefiles which always will be included if they exist.
 128 my @static_included_rulefiles = ('local.rules', 'whitelist.rules');
 129
 130 # Array which contains a list of allways enabled application layer protocols.
 131 my @static_enabled_app_layer_protos = ('app-layer', 'decoder', 'files', 'stream');
 132
 133 # Hash which allows to convert the download type (dl_type) to a file suffix.
 134 my %dl_type_to_suffix = (
 135         "archive" => ".tar.gz",
 136         "plain" => ".rules",
 137 );
 138
 139 # Hash to translate an application layer protocol to the application name.
 140 my %tr_app_layer_proto = (
 141         "ikev2" => "ipsec",
 142         "krb5" => "kerberos",
 143 );
 144
 145 #
 146 ## Function to check and create all IDS related files, if the does not exist.
 147 #
 148 sub check_and_create_filelayout() {
 149         # Check if the files exist and if not, create them.
 150         unless (-f "$oinkmaster_provider_includes_file") { &create_empty_file($oinkmaster_provider_includes_file); }
 151         unless (-f "$modify_sids_file") { &create_empty_file($modify_sids_file); }
 152         unless (-f "$suricata_used_providers_file") { &create_empty_file($suricata_used_providers_file); }
 153         unless (-f "$suricata_default_rulefiles_file") { &create_empty_file($suricata_default_rulefiles_file); }
 154         unless (-f "$ids_settings_file") { &create_empty_file($ids_settings_file); }
 155         unless (-f "$providers_settings_file") { &create_empty_file($providers_settings_file); }
 156         unless (-f "$whitelist_file" ) { &create_empty_file($whitelist_file); }
 157 }
 158
 159 #
 160 ## Function to get a list of all available ruleset providers.
 161 ##
 162 ## They will be returned as a sorted array.
 163 #
 164 sub get_ruleset_providers() {
 165         my @providers;
 166
 167         # Loop through the hash of providers.
 168         foreach my $provider ( keys %IDS::Ruleset::Providers ) {
 169                 # Add the provider to the array.
 170                 push(@providers, $provider);
 171         }
 172
 173         # Sort and return the array.
 174         return sort(@providers);
 175 }
 176
 177 #
 178 ## Function to get a list of all enabled ruleset providers.
 179 ##
 180 ## They will be returned as an array.
 181 #
 182 sub get_enabled_providers () {
 183         my %used_providers = ();
 184
 185         # Array to store the enabled providers.
 186         my @enabled_providers = ();
 187
 188         # Read-in the providers config file.
 189         &General::readhasharray("$providers_settings_file", \%used_providers);
 190
 191         # Loop through the hash of used_providers.
 192         foreach my $id (keys %used_providers) {
 193                 # Skip disabled providers.
 194                 next unless ($used_providers{$id}[3] eq "enabled");
 195
 196                 # Grab the provider handle.
 197                 my $provider = "$used_providers{$id}[0]";
 198
 199                 # Add the provider to the array of enabled providers.
 200                 push(@enabled_providers, $provider);
 201         }
 202
 203         # Return the array.
 204         return @enabled_providers;
 205 }
 206
 207 #
 208 ## Function for checking if at least 300MB of free disk space are available
 209 ## on the "/var" partition.
 210 #
 211 sub checkdiskspace () {
 212         # Call diskfree to gather the free disk space of /var.
 213         my @df = &General::system_output("/bin/df", "-B", "M", "/var");
 214
 215         # Loop through the output.
 216         foreach my $line (@df) {
 217                 # Ignore header line.
 218                 next if $line =~ m/^Filesystem/;
 219
 220                 # Search for a line with the device information.
 221                 if ($line =~ m/dev/ ) {
 222                         # Split the line into single pieces.
 223                         my @values = split(' ', $line);
 224                         my ($filesystem, $blocks, $used, $available, $used_perenctage, $mounted_on) = @values;
 225
 226                         # Check if the available disk space is more than 300MB.
 227                         if ($available < 300) {
 228                                 # Log error to syslog.
 229                                 &_log_to_syslog("Not enough free disk space on /var. Only $available MB from 300 MB available.");
 230
 231                                 # Exit function and return "1" - False.
 232                                 return 1;
 233                         }
 234                 }
 235         }
 236
 237         # Everything okay, return nothing.
 238         return;
 239 }
 240
 241 #
 242 ## This function is responsible for downloading the configured IDS rulesets or if no one is specified
 243 ## all configured rulesets will be downloaded.
 244 ##
 245 ## * At first it gathers all configured ruleset providers, initialize the downloader and sets an
 246 ##   upstream proxy if configured.
 247 ## * After that, the given ruleset or in case all rulesets should be downloaded, it will determine wether it
 248 ##   is enabled or not.
 249 ## * The next step will be to generate the final download url, by obtaining the URL for the desired
 250 ##   ruleset, add the settings for the upstream proxy.
 251 ## * Finally the function will grab all the rules files or tarballs from the servers.
 252 #
 253 sub downloadruleset ($) {
 254         my ($provider) = @_;
 255
 256         # If no provider is given default to "all".
 257         $provider //= 'all';
 258
 259         # Hash to store the providers and access id's, for which rules should be downloaded.
 260         my %sheduled_providers = ();
 261
 262         # Get used provider settings.
 263         my %used_providers = ();
 264         &General::readhasharray("$providers_settings_file", \%used_providers);
 265
 266         # Check if a ruleset has been configured.
 267         unless(%used_providers) {
 268                 # Log that no ruleset has been configured and abort.
 269                 &_log_to_syslog("No ruleset provider has been configured.");
 270
 271                 # Return "1".
 272                 return 1;
 273         }
 274
 275         # Read proxysettings.
 276         my %proxysettings=();
 277         &General::readhash("${General::swroot}/proxy/settings", \%proxysettings);
 278
 279         # Load required perl module to handle the download.
 280         use LWP::UserAgent;
 281
 282         # Init the download module.
 283         #
 284         # Request SSL hostname verification and specify path
 285         # to the CA file.
 286         my $downloader = LWP::UserAgent->new(
 287                 ssl_opts => {
 288                         SSL_ca_file     => '/etc/ssl/cert.pem',
 289                         verify_hostname => 1,
 290                 }
 291         );
 292
 293         # Set timeout to 10 seconds.
 294         $downloader->timeout(10);
 295
 296         # Check if an upstream proxy is configured.
 297         if ($proxysettings{'UPSTREAM_PROXY'}) {
 298                 my $proxy_url;
 299
 300                 $proxy_url = "http://";
 301
 302                 # Check if the proxy requires authentication.
 303                 if (($proxysettings{'UPSTREAM_USER'}) && ($proxysettings{'UPSTREAM_PASSWORD'})) {
 304                         $proxy_url .= "$proxysettings{'UPSTREAM_USER'}\:$proxysettings{'UPSTREAM_PASSWORD'}\@";
 305                 }
 306
 307                 # Add proxy server address and port.
 308                 $proxy_url .= $proxysettings{'UPSTREAM_PROXY'};
 309
 310                 # Setup proxy settings.
 311                 $downloader->proxy(['http', 'https'], $proxy_url);
 312         }
 313
 314         # Loop through the hash of configured providers.
 315         foreach my $id ( keys %used_providers ) {
 316                 # Skip providers which are not enabled.
 317                 next if ($used_providers{$id}[3] ne "enabled");
 318
 319                 # Obtain the provider handle.
 320                 my $provider_handle = $used_providers{$id}[0];
 321
 322                 # Handle update off all providers.
 323                 if (($provider eq "all") || ($provider_handle eq "$provider")) {
 324                         # Add provider handle and it's id to the hash of sheduled providers.
 325                         $sheduled_providers{$provider_handle} = $id;
 326                 }
 327         }
 328
 329         # Loop through the hash of sheduled providers.
 330         foreach my $provider ( keys %sheduled_providers) {
 331                 # Log download/update of the ruleset.
 332                 &_log_to_syslog("Downloading ruleset for provider: $provider.");
 333
 334                 # Grab the download url for the provider.
 335                 my $url = $IDS::Ruleset::Providers{$provider}{'dl_url'};
 336
 337                 # Check if the provider requires a subscription.
 338                 if ($IDS::Ruleset::Providers{$provider}{'requires_subscription'} eq "True") {
 339                         # Grab the previously stored access id for the provider from hash.
 340                         my $id = $sheduled_providers{$provider};
 341
 342                         # Grab the subscription code.
 343                         my $subscription_code = $used_providers{$id}[1];
 344
 345                         # Add the subscription code to the download url.
 346                         $url =~ s/\<subscription_code\>/$subscription_code/g;
 347
 348                 }
 349
 350                 # Abort if no url could be determined for the provider.
 351                 unless ($url) {
 352                         # Log error and abort.
 353                         &_log_to_syslog("Unable to gather a download URL for the selected ruleset provider.");
 354                         return 1;
 355                 }
 356
 357                 # Variable to store the filesize of the remote object.
 358                 my $remote_filesize;
 359
 360                 # The sourcfire (snort rules) does not allow to send "HEAD" requests, so skip this check
 361                 # for this webserver.
 362                 #
 363                 # Check if the ruleset source contains "snort.org".
 364                 unless ($url =~ /\.snort\.org/) {
 365                         # Pass the requrested url to the downloader.
 366                         my $request = HTTP::Request->new(HEAD => $url);
 367
 368                         # Accept the html header.
 369                         $request->header('Accept' => 'text/html');
 370
 371                         # Perform the request and fetch the html header.
 372                         my $response = $downloader->request($request);
 373
 374                         # Check if there was any error.
 375                         unless ($response->is_success) {
 376                                 # Obtain error.
 377                                 my $error = $response->status_line();
 378
 379                                 # Log error message.
 380                                 &_log_to_syslog("Unable to download the ruleset. \($error\)");
 381
 382                                 # Return "1" - false.
 383                                 return 1;
 384                         }
 385
 386                         # Assign the fetched header object.
 387                         my $header = $response->headers();
 388
 389                         # Grab the remote file size from the object and store it in the
 390                         # variable.
 391                         $remote_filesize = $header->content_length;
 392                 }
 393
 394                 # Load perl module to deal with temporary files.
 395                 use File::Temp;
 396
 397                 # Generate temporary file name, located in "/var/tmp" and with a suffix of ".tmp".
 398                 my $tmp = File::Temp->new( SUFFIX => ".tmp", DIR => "/var/tmp/", UNLINK => 0 );
 399                 my $tmpfile = $tmp->filename();
 400
 401                 # Pass the requested url to the downloader.
 402                 my $request = HTTP::Request->new(GET => $url);
 403
 404                 # Perform the request and save the output into the tmpfile.
 405                 my $response = $downloader->request($request, $tmpfile);
 406
 407                 # Check if there was any error.
 408                 unless ($response->is_success) {
 409                         # Obtain error.
 410                         my $error = $response->content;
 411
 412                         # Log error message.
 413                         &_log_to_syslog("Unable to download the ruleset. \($error\)");
 414
 415                         # Return "1" - false.
 416                         return 1;
 417                 }
 418
 419                 # Load perl stat module.
 420                 use File::stat;
 421
 422                 # Perform stat on the tmpfile.
 423                 my $stat = stat($tmpfile);
 424
 425                 # Grab the local filesize of the downloaded tarball.
 426                 my $local_filesize = $stat->size;
 427
 428                 # Check if both file sizes match.
 429                 if (($remote_filesize) && ($remote_filesize ne $local_filesize)) {
 430                         # Log error message.
 431                         &_log_to_syslog("Unable to completely download the ruleset. ");
 432                         &_log_to_syslog("Only got $local_filesize Bytes instead of $remote_filesize Bytes. ");
 433
 434                         # Delete temporary file.
 435                         unlink("$tmpfile");
 436
 437                         # Return "1" - false.
 438                         return 1;
 439                 }
 440
 441                 # Genarate and assign file name and path to store the downloaded rules file.
 442                 my $dl_rulesfile = &_get_dl_rulesfile($provider);
 443
 444                 # Check if a file name could be obtained.
 445                 unless ($dl_rulesfile) {
 446                         # Log error message.
 447                         &_log_to_syslog("Unable to store the downloaded rules file. ");
 448
 449                         # Delete downloaded temporary file.
 450                         unlink("$tmpfile");
 451
 452                         # Return "1" - false.
 453                         return 1;
 454                 }
 455
 456                 # Load file copy module, which contains the move() function.
 457                 use File::Copy;
 458
 459                 # Overwrite the may existing rulefile or tarball with the downloaded one.
 460                 move("$tmpfile", "$dl_rulesfile");
 461
 462                 # Delete temporary file.
 463                 unlink("$tmpfile");
 464
 465                 # Set correct ownership for the tarball.
 466                 set_ownership("$dl_rulesfile");
 467         }
 468
 469         # If we got here, everything worked fine. Return nothing.
 470         return;
 471 }
 472
 473 #
 474 ## Function to extract a given ruleset.
 475 ##
 476 ## In case the ruleset provider offers a plain file, it simply will
 477 ## be copied.
 478 #
 479 sub extractruleset ($) {
 480         my ($provider) = @_;
 481
 482         # Load perl module to deal with archives.
 483         use Archive::Tar;
 484
 485         # Disable chown functionality when uncompressing files.
 486         $Archive::Tar::CHOWN = "0";
 487
 488         # Load perl module to deal with files and path.
 489         use File::Basename;
 490
 491         # Load perl module for file copying.
 492         use File::Copy;
 493
 494         # Get full path and downloaded rulesfile for the given provider.
 495         my $tarball = &_get_dl_rulesfile($provider);
 496
 497         # Check if the file exists.
 498         unless (-f $tarball) {
 499                 &_log_to_syslog("Could not find ruleset file: $tarball");
 500
 501                 # Return nothing.
 502                 return;
 503         }
 504
 505         # Check if the temporary directories exist, otherwise create them.
 506         mkdir("$tmp_directory") unless (-d "$tmp_directory");
 507         mkdir("$tmp_rules_directory") unless (-d "$tmp_rules_directory");
 508         mkdir("$tmp_conf_directory") unless (-d "$tmp_conf_directory");
 509
 510         # Omit the type (dl_type) of the stored ruleset.
 511         my $type = $IDS::Ruleset::Providers{$provider}{'dl_type'};
 512
 513         # Handle the different ruleset types.
 514         if ($type eq "plain") {
 515                 # Generate destination filename an full path.
 516                 my $destination = "$tmp_rules_directory/$provider\-ruleset.rules";
 517
 518                 # Copy the file into the temporary rules directory.
 519                 copy($tarball, $destination);
 520
 521         } elsif ( $type eq "archive") {
 522                 # Initialize the tar module.
 523                 my $tar = Archive::Tar->new($tarball);
 524
 525                 # Get the filelist inside the tarball.
 526                 my @packed_files = $tar->list_files;
 527
 528                 # Loop through the filelist.
 529                 foreach my $packed_file (@packed_files) {
 530                         my $destination;
 531
 532                         # Splitt the packed file into chunks.
 533                         my $file = fileparse($packed_file);
 534
 535                         # Handle msg-id.map file.
 536                         if ("$file" eq "sid-msg.map") {
 537                                 # Set extract destination to temporary config_dir.
 538                                 $destination = "$tmp_conf_directory/$provider\-sid-msg.map";
 539
 540                         # Handle classification.conf
 541                         } elsif ("$file" eq "classification.config") {
 542                                 # Set extract destination to temporary config_dir.
 543                                 $destination = "$tmp_conf_directory/$provider\-classification.config";
 544
 545                         # Handle rules files.
 546                         } elsif ($file =~ m/\.rules$/) {
 547                                 my $rulesfilename;
 548
 549                                 # Splitt the filename into chunks.
 550                                 my @filename = split("-", $file);
 551
 552                                 # Reverse the array.
 553                                 @filename = reverse(@filename);
 554
 555                                 # Get the amount of elements in the array.
 556                                 my $elements = @filename;
 557
 558                                 # Remove last element of the hash.
 559                                 # It contains the vendor name, which will be replaced.
 560                                 if ($elements >= 3) {
 561                                 # Remove last element from hash.
 562                                         pop(@filename);
 563                                 }
 564
 565                                 # Check if the last element of the filename does not
 566                                 # contain the providers name.
 567                                 if ($filename[-1] ne "$provider") {
 568                                         # Add provider name as last element.
 569                                         push(@filename, $provider);
 570                                 }
 571
 572                                 # Reverse the array back.
 573                                 @filename = reverse(@filename);
 574
 575                                 # Generate the name for the rulesfile.
 576                                 $rulesfilename = join("-", @filename);
 577
 578                                 # Set extract destination to temporaray rules_dir.
 579                                 $destination = "$tmp_rules_directory/$rulesfilename";
 580                         } else {
 581                                 # Skip all other files.
 582                                 next;
 583                         }
 584
 585                         # Check if the destination file exists.
 586                         unless(-e "$destination") {
 587                                 # Extract the file to the temporary directory.
 588                                 $tar->extract_file("$packed_file", "$destination");
 589                         } else {
 590                                 # Load perl module to deal with temporary files.
 591                                 use File::Temp;
 592
 593                                 # Generate temporary file name, located in the temporary rules directory and a suffix of ".tmp".
 594                                 my $tmp = File::Temp->new( SUFFIX => ".tmp", DIR => "$tmp_rules_directory", UNLINK => 0 );
 595                                 my $tmpfile = $tmp->filename();
 596
 597                                 # Extract the file to the new temporary file name.
 598                                 $tar->extract_file("$packed_file", "$tmpfile");
 599
 600                                 # Open the the existing file.
 601                                 open(DESTFILE, ">>", "$destination") or die "Could not open $destination. $!\n";
 602                                 open(TMPFILE, "<", "$tmpfile") or die "Could not open $tmpfile. $!\n";
 603
 604                                 # Loop through the content of the temporary file.
 605                                 while (<TMPFILE>) {
 606                                         # Append the content line by line to the destination file.
 607                                         print DESTFILE "$_";
 608                                 }
 609
 610                                 # Close the file handles.
 611                                 close(TMPFILE);
 612                                 close(DESTFILE);
 613
 614                                 # Remove the temporary file.
 615                                 unlink("$tmpfile");
 616                         }
 617                 }
 618         }
 619 }
 620
 621 #
 622 ## A wrapper function to call the oinkmaster script, setup the rules structues and
 623 ## call the functions to merge the additional config files. (classification, sid-msg, etc.).
 624 #
 625 sub oinkmaster () {
 626         # Check if the files in rulesdir have the correct permissions.
 627         &_check_rulesdir_permissions();
 628
 629         # Cleanup the rules directory before filling it with the new rulests.
 630         &_cleanup_rulesdir();
 631
 632         # Get all enabled providers.
 633         my @enabled_providers = &get_enabled_providers();
 634
 635         # Loop through the array of enabled providers.
 636         foreach my $provider (@enabled_providers) {
 637                 # Call the extractruleset function.
 638                 &extractruleset($provider);
 639         }
 640
 641         # Load perl module to talk to the kernel syslog.
 642         use Sys::Syslog qw(:DEFAULT setlogsock);
 643
 644         # Establish the connection to the syslog service.
 645         openlog('oinkmaster', 'cons,pid', 'user');
 646
 647         # Call oinkmaster to generate ruleset.
 648         open(OINKMASTER, "/usr/local/bin/oinkmaster.pl -s -u dir://$tmp_rules_directory -C $settingsdir/oinkmaster.conf -o $rulespath 2>&1 |") or die "Could not execute oinkmaster $!\n";
 649
 650         # Log output of oinkmaster to syslog.
 651         while(<OINKMASTER>) {
 652                 # The syslog function works best with an array based input,
 653                 # so generate one before passing the message details to syslog.
 654                 my @syslog = ("INFO", "$_");
 655
 656                 # Send the log message.
 657                 syslog(@syslog);
 658         }
 659
 660         # Close the pipe to oinkmaster process.
 661         close(OINKMASTER);
 662
 663         # Close the log handle.
 664         closelog();
 665
 666         # Call function to merge the classification files.
 667         &merge_classifications(@enabled_providers);
 668
 669         # Call function to merge the sid to message mapping files.
 670         &merge_sid_msg(@enabled_providers);
 671
 672         # Cleanup temporary directory.
 673         &cleanup_tmp_directory();
 674 }
 675
 676 #
 677 ## Function to merge the classifications for a given amount of providers and write them
 678 ## to the classifications file.
 679 #
 680 sub merge_classifications(@) {
 681         my @providers = @_;
 682
 683         # Hash to store all collected classifications.
 684         my %classifications = ();
 685
 686         # Loop through the given array of providers.
 687         foreach my $provider (@providers) {
 688                 # Generate full path to classification file.
 689                 my $classification_file = "$tmp_conf_directory/$provider\-classification.config";
 690
 691                 # Skip provider if no classification file exists.
 692                 next unless (-f "$classification_file");
 693
 694                 # Open the classification file.
 695                 open(CLASSIFICATION, $classification_file) or die "Could not open file $classification_file. $!\n";
 696
 697                 # Loop through the file content.
 698                 while(<CLASSIFICATION>) {
 699                         # Parse the file and grab the classification details.
 700                         if ($_ =~/.*config classification\: (.*)/) {
 701                                 # Split the grabbed details.
 702                                 my ($short_name, $short_desc, $priority) = split("\,", $1);
 703
 704                                 # Check if the grabbed classification is allready known and the priority value is greater
 705                                 # than the stored one (which causes less priority in the IDS).
 706                                 if (($classifications{$short_name}) && ($classifications{$short_name}[1] >= $priority)) {
 707                                         #Change the priority value to the stricter one.
 708                                         $classifications{$short_name} = [ "$classifications{$short_name}[0]", "$priority" ];
 709                                 } else {
 710                                         # Add the classification to the hash.
 711                                         $classifications{$short_name} = [ "$short_desc", "$priority" ];
 712                                 }
 713                         }
 714                 }
 715
 716                 # Close the file.
 717                 close(CLASSIFICATION);
 718         }
 719
 720         # Open classification file for writing.
 721         open(FILE, ">", "$classification_file") or die "Could not write to $classification_file. $!\n";
 722
 723         # Print notice about autogenerated file.
 724         print FILE "#Autogenerated file. Any custom changes will be overwritten!\n\n";
 725
 726         # Sort and loop through the hash of classifications.
 727         foreach my $key (sort keys %classifications) {
 728                 # Assign some nice variable names for the items.
 729                 my $short_name = $key;
 730                 my $short_desc = $classifications{$key}[0];
 731                 my $priority = $classifications{$key}[1];
 732
 733                 # Write the classification to the file.
 734                 print FILE "config classification: $short_name,$short_desc,$priority\n";
 735         }
 736
 737         # Close file handle.
 738         close(FILE);
 739 }
 740
 741 #
 742 ## Function to merge the "sid to message mapping" files of various given providers.
 743 #
 744 sub merge_sid_msg (@) {
 745         my @providers = @_;
 746
 747         # Hash which contains all the sid to message mappings.
 748         my %mappings = ();
 749
 750         # Loop through the array of given providers.
 751         foreach my $provider (@providers) {
 752                 # Generate full path and filename.
 753                 my $sid_msg_file = "$tmp_conf_directory/$provider\-sid-msg.map";
 754
 755                 # Skip provider if no sid to msg mapping file for this provider exists.
 756                 next unless (-f $sid_msg_file);
 757
 758                 # Open the file.
 759                 open(MAPPING, $sid_msg_file) or die "Could not open $sid_msg_file. $!\n";
 760
 761                 # Loop through the file content.
 762                 while (<MAPPING>) {
 763                         # Remove newlines.
 764                         chomp($_);
 765
 766                         # Skip lines which do not start with a number,
 767                         next unless ($_ =~ /^\d+/);
 768
 769                         # Split line content and assign it to an array.
 770                         my @line = split(/ \|\| /, $_);
 771
 772                         # Grab the first element (and remove it) from the line array.
 773                         # It contains the sid.
 774                         my $sid = shift(@line);
 775
 776                         # Store the grabbed sid and the remain array as hash value.
 777                         # It still contains the messages, references etc.
 778                         $mappings{$sid} = [@line];
 779                 }
 780
 781                 # Close file handle.
 782                 close(MAPPING);
 783         }
 784
 785         # Open mappings file for writing.
 786         open(FILE, ">", $sid_msg_file) or die "Could not write $sid_msg_file. $!\n";
 787
 788         # Write notice about autogenerated file.
 789         print FILE "#Autogenerated file. Any custom changes will be overwritten!\n\n";
 790
 791         # Loop through the hash of mappings.
 792         foreach my $sid ( sort keys %mappings) {
 793                 # Grab data for the sid.
 794                 my @data = @{$mappings{$sid}};
 795
 796                 # Add the sid to the data array.
 797                 unshift(@data, $sid);
 798
 799                 # Generate line.
 800                 my $line = join(" \|\| ", @data);
 801
 802                 print FILE "$line\n";
 803
 804         }
 805
 806         # Close file handle.
 807         close(FILE);
 808 }
 809
 810 #
 811 ## A very tiny function to move an extracted ruleset from the temporary directory into
 812 ## the rules directory.
 813 #
 814 sub move_tmp_ruleset() {
 815         # Load perl module.
 816         use File::Copy;
 817
 818         # Do a directory listing of the temporary directory.
 819         opendir  DH, $tmp_rules_directory;
 820
 821         # Loop over all files.
 822         while(my $file = readdir DH) {
 823                 # Move them to the rules directory.
 824                 move "$tmp_rules_directory/$file" , "$rulespath/$file";
 825         }
 826
 827         # Close directory handle.
 828         closedir DH;
 829 }
 830
 831 #
 832 ## Function to cleanup the temporary IDS directroy.
 833 #
 834 sub cleanup_tmp_directory () {
 835         # Load rmtree() function from file path perl module.
 836         use File::Path 'rmtree';
 837
 838         # Delete temporary directory and all containing files.
 839         rmtree([ "$tmp_directory" ]);
 840 }
 841
 842 #
 843 ## Function to do all the logging stuff if the downloading or updating of the ruleset fails.
 844 #
 845 sub log_error ($) {
 846         my ($error) = @_;
 847
 848         # Remove any newline.
 849         chomp($error);
 850
 851         # Call private function to log the error message to syslog.
 852         &_log_to_syslog($error);
 853
 854         # Call private function to write/store the error message in the storederrorfile.
 855         &_store_error_message($error);
 856 }
 857
 858 #
 859 ## Function to log a given error message to the kernel syslog.
 860 #
 861 sub _log_to_syslog ($) {
 862         my ($message) = @_;
 863
 864         # Load perl module to talk to the kernel syslog.
 865         use Sys::Syslog qw(:DEFAULT setlogsock);
 866
 867         # The syslog function works best with an array based input,
 868         # so generate one before passing the message details to syslog.
 869         my @syslog = ("ERR", "<ERROR> $message");
 870
 871         # Establish the connection to the syslog service.
 872         openlog('oinkmaster', 'cons,pid', 'user');
 873
 874         # Send the log message.
 875         syslog(@syslog);
 876
 877         # Close the log handle.
 878         closelog();
 879 }
 880
 881 #
 882 ## Private function to write a given error message to the storederror file.
 883 #
 884 sub _store_error_message ($) {
 885         my ($message) = @_;
 886
 887         # Remove any newline.
 888         chomp($message);
 889
 890         # Open file for writing.
 891         open (ERRORFILE, ">$storederrorfile") or die "Could not write to $storederrorfile. $!\n";
 892
 893         # Write error to file.
 894         print ERRORFILE "$message\n";
 895
 896         # Close file.
 897         close (ERRORFILE);
 898
 899         # Set correct ownership for the file.
 900         &set_ownership("$storederrorfile");
 901 }
 902
 903 #
 904 ## Private function to get the path and filename for a downloaded ruleset by a given provider.
 905 #
 906 sub _get_dl_rulesfile($) {
 907         my ($provider) = @_;
 908
 909         # Gather the download type for the given provider.
 910         my $dl_type = $IDS::Ruleset::Providers{$provider}{'dl_type'};
 911
 912         # Obtain the file suffix for the download file type.
 913         my $suffix = $dl_type_to_suffix{$dl_type};
 914
 915         # Check if a suffix has been found.
 916         unless ($suffix) {
 917                 # Abort return - nothing.
 918                 return;
 919         }
 920
 921         # Generate the full filename and path for the stored rules file.
 922         my $rulesfile = "$dl_rules_path/$dl_rulesfile_prefix-$provider$suffix";
 923
 924         # Return the generated filename.
 925         return $rulesfile;
 926 }
 927
 928 #
 929 ## Tiny function to delete the stored ruleset file or tarball for a given provider.
 930 #
 931 sub drop_dl_rulesfile ($) {
 932         my ($provider) = @_;
 933
 934         # Gather the full path and name of the stored rulesfile.
 935         my $rulesfile = &_get_dl_rulesfile($provider);
 936
 937         # Check if the given rulesfile exists.
 938         if (-f $rulesfile) {
 939                 # Delete the stored rulesfile.
 940                 unlink($rulesfile) or die "Could not delete $rulesfile. $!\n";
 941         }
 942 }
 943
 944 #
 945 ## Tiny function to get/generate the full path and filename for the providers oinkmaster
 946 ## modified sids file.
 947 #
 948 sub get_oinkmaster_provider_modified_sids_file ($) {
 949         my ($provider) = @_;
 950
 951         # Generate the filename.
 952         my $filename = "$settingsdir/oinkmaster-$provider-modified-sids.conf";
 953
 954         # Return the filename.
 955         return $filename;
 956 }
 957
 958 #
 959 ## Function to directly altering the oinkmaster provider includes file.
 960 ##
 961 ## Requires tha acition "remove" or "add" and a provider handle.
 962 #
 963 sub alter_oinkmaster_provider_includes_file ($$) {
 964         my ($action, $provider) = @_;
 965
 966         # Call function to get the path and name for the given providers
 967         # oinkmaster modified sids file.
 968         my $provider_modified_sids_file = &get_oinkmaster_provider_modified_sids_file($provider);
 969
 970         # Open the file for reading..
 971         open (FILE, $oinkmaster_provider_includes_file) or die "Could not read $oinkmaster_provider_includes_file. $!\n";
 972
 973         # Read-in file content.
 974         my @lines = <FILE>;
 975
 976         # Close file after reading.
 977         close(FILE);
 978
 979         # Re-open the file for writing.
 980         open(FILE, ">", $oinkmaster_provider_includes_file) or die "Could not write to $oinkmaster_provider_includes_file. $!\n";
 981
 982         # Loop through the file content.
 983         foreach my $line (@lines) {
 984                 # Remove newlines.
 985                 chomp($line);
 986
 987                 # Skip line if we found our given provider and the action should be remove.
 988                 next if (($line =~ /$provider/) && ($action eq "remove"));
 989
 990                 # Write the read-in line back to the file.
 991                 print FILE "$line\n";
 992         }
 993
 994         # Check if the file exists and add the provider if requested.
 995         if ((-f $provider_modified_sids_file) && ($action eq "add")) {
 996                 print FILE "include $provider_modified_sids_file\n";
 997         }
 998
 999         # Close file handle.
1000         close(FILE);
1001 }
1002
1003 #
1004 ## Function to read-in the given enabled or disables sids file.
1005 #
1006 sub read_enabled_disabled_sids_file($) {
1007         my ($file) = @_;
1008
1009         # Temporary hash to store the sids and their state. It will be
1010         # returned at the end of this function.
1011         my %temphash;
1012
1013         # Open the given filename.
1014         open(FILE, "$file") or die "Could not open $file. $!\n";
1015
1016         # Loop through the file.
1017         while(<FILE>) {
1018                 # Remove newlines.
1019                 chomp $_;
1020
1021                 # Skip blank lines.
1022                 next if ($_ =~ /^\s*$/);
1023
1024                 # Skip coments.
1025                 next if ($_ =~ /^\#/);
1026
1027                 # Splitt line into sid and state part.
1028                 my ($state, $sid) = split(" ", $_);
1029
1030                 # Skip line if the sid is not numeric.
1031                 next unless ($sid =~ /\d+/ );
1032
1033                 # Check if the sid was enabled.
1034                 if ($state eq "enablesid") {
1035                         # Add the sid and its state as enabled to the temporary hash.
1036                         $temphash{$sid} = "enabled";
1037                 # Check if the sid was disabled.
1038                 } elsif ($state eq "disablesid") {
1039                         # Add the sid and its state as disabled to the temporary hash.
1040                         $temphash{$sid} = "disabled";
1041                 # Invalid state - skip the current sid and state.
1042                 } else {
1043                         next;
1044                 }
1045         }
1046
1047         # Close filehandle.
1048         close(FILE);
1049
1050         # Return the hash.
1051         return %temphash;
1052 }
1053
1054 #
1055 ## Function to check if the IDS is running.
1056 #
1057 sub ids_is_running () {
1058         if(-f $idspidfile) {
1059                 # Open PID file for reading.
1060                 open(PIDFILE, "$idspidfile") or die "Could not open $idspidfile. $!\n";
1061
1062                 # Grab the process-id.
1063                 my $pid = <PIDFILE>;
1064
1065                 # Close filehandle.
1066                 close(PIDFILE);
1067
1068                 # Remove any newline.
1069                 chomp($pid);
1070
1071                 # Check if a directory for the process-id exists in proc.
1072                 if(-d "/proc/$pid") {
1073                         # The IDS daemon is running return the process id.
1074                         return $pid;
1075                 }
1076         }
1077
1078         # Return nothing - IDS is not running.
1079         return;
1080 }
1081
1082 #
1083 ## Function to call suricatactrl binary with a given command.
1084 #
1085 sub call_suricatactrl ($) {
1086         # Get called option.
1087         my ($option, $interval) = @_;
1088
1089         # Loop through the array of supported commands and check if
1090         # the given one is part of it.
1091         foreach my $cmd (@suricatactrl_cmds) {
1092                 # Skip current command unless the given one has been found.
1093                 next unless($cmd eq $option);
1094
1095                 # Check if the given command is "cron".
1096                 if ($option eq "cron") {
1097                         # Check if an interval has been given.
1098                         if ($interval) {
1099                                 # Check if the given interval is valid.
1100                                 foreach my $element (@cron_intervals) {
1101                                         # Skip current element until the given one has been found.
1102                                         next unless($element eq $interval);
1103
1104                                         # Call the suricatactrl binary and pass the "cron" command
1105                                         # with the requrested interval.
1106                                         &General::system("$suricatactrl", "$option", "$interval");
1107
1108                                         # Return "1" - True.
1109                                         return 1;
1110                                 }
1111                         }
1112
1113                         # If we got here, the given interval is not supported or none has been given. - Return nothing.
1114                         return;
1115                 } else {
1116                         # Call the suricatactrl binary and pass the requrested
1117                         # option to it.
1118                         &General::system("$suricatactrl", "$option");
1119
1120                         # Return "1" - True.
1121                         return 1;
1122                 }
1123         }
1124
1125         # Command not found - return nothing.
1126         return;
1127 }
1128
1129 #
1130 ## Function to create a new empty file.
1131 #
1132 sub create_empty_file($) {
1133         my ($file) = @_;
1134
1135         # Check if the given file exists.
1136         if(-e $file) {
1137                 # Do nothing to prevent from overwriting existing files.
1138                 return;
1139         }
1140
1141         # Open the file for writing.
1142         open(FILE, ">$file") or die "Could not write to $file. $!\n";
1143
1144         # Close file handle.
1145         close(FILE);
1146
1147         # Return true.
1148         return 1;
1149 }
1150
1151 #
1152 ## Private function to check if the file permission of the rulespath are correct.
1153 ## If not, call suricatactrl to fix them.
1154 #
1155 sub _check_rulesdir_permissions() {
1156         # Check if the rulepath main directory is writable.
1157         unless (-W $rulespath) {
1158                 # If not call suricatctrl to fix it.
1159                 &call_suricatactrl("fix-rules-dir");
1160         }
1161
1162         # Open snort rules directory and do a directory listing.
1163         opendir(DIR, $rulespath) or die $!;
1164         # Loop through the direcory.
1165         while (my $file = readdir(DIR)) {
1166                 # We only want files.
1167                 next unless (-f "$rulespath/$file");
1168
1169                 # Check if the file is writable by the user.
1170                 if (-W "$rulespath/$file") {
1171                         # Everything is okay - go on to the next file.
1172                         next;
1173                 } else {
1174                         # There are wrong permissions, call suricatactrl to fix it.
1175                         &call_suricatactrl("fix-rules-dir");
1176                 }
1177         }
1178 }
1179
1180 #
1181 ## Private function to cleanup the directory which contains
1182 ## the IDS rules, before extracting and modifing the new ruleset.
1183 #
1184 sub _cleanup_rulesdir() {
1185         # Open rules directory and do a directory listing.
1186         opendir(DIR, $rulespath) or die $!;
1187
1188         # Loop through the direcory.
1189         while (my $file = readdir(DIR)) {
1190                 # We only want files.
1191                 next unless (-f "$rulespath/$file");
1192
1193                 # Skip rules file for whitelisted hosts.
1194                 next if ("$rulespath/$file" eq $whitelist_file);
1195
1196                 # Skip rules file with local rules.
1197                 next if ("$rulespath/$file" eq $local_rules_file);
1198
1199                 # Delete the current processed file, if not, exit this function
1200                 # and return an error message.
1201                 unlink("$rulespath/$file") or return "Could not delete $rulespath/$file. $!\n";
1202         }
1203
1204         # Return nothing;
1205         return;
1206 }
1207
1208 #
1209 ## Function to generate the file which contains the home net information.
1210 #
1211 sub generate_home_net_file() {
1212         my %netsettings;
1213
1214         # Read-in network settings.
1215         &General::readhash("${General::swroot}/ethernet/settings", \%netsettings);
1216
1217         # Get available network zones.
1218         my @network_zones = &Network::get_available_network_zones();
1219
1220         # Temporary array to store network address and prefix of the configured
1221         # networks.
1222         my @networks;
1223
1224         # Loop through the array of available network zones.
1225         foreach my $zone (@network_zones) {
1226                 # Check if the current processed zone is red.
1227                 if($zone eq "red") {
1228                         # Grab the IP-address of the red interface.
1229                         my $red_address = &get_red_address();
1230
1231                         # Check if an address has been obtained.
1232                         if ($red_address) {
1233                                 # Generate full network string.
1234                                 my $red_network = join("/", $red_address, "32");
1235
1236                                 # Add the red network to the array of networks.
1237                                 push(@networks, $red_network);
1238                         }
1239
1240                         # Check if the configured RED_TYPE is static.
1241                         if ($netsettings{'RED_TYPE'} eq "STATIC") {
1242                                 # Get configured and enabled aliases.
1243                                 my @aliases = &get_aliases();
1244
1245                                 # Loop through the array.
1246                                 foreach my $alias (@aliases) {
1247                                         # Add "/32" prefix.
1248                                         my $network = join("/", $alias, "32");
1249
1250                                         # Add the generated network to the array of networks.
1251                                         push(@networks, $network);
1252                                 }
1253                         }
1254                 # Process remaining network zones.
1255                 } else {
1256                         # Convert current zone name into upper case.
1257                         $zone = uc($zone);
1258
1259                         # Generate key to access the required data from the netsettings hash.
1260                         my $zone_netaddress = $zone . "_NETADDRESS";
1261                         my $zone_netmask = $zone . "_NETMASK";
1262
1263                         # Obtain the settings from the netsettings hash.
1264                         my $netaddress = $netsettings{$zone_netaddress};
1265                         my $netmask = $netsettings{$zone_netmask};
1266
1267                         # Convert the subnetmask into prefix notation.
1268                         my $prefix = &Network::convert_netmask2prefix($netmask);
1269
1270                         # Generate full network string.
1271                         my $network = join("/", $netaddress,$prefix);
1272
1273                         # Check if the network is valid.
1274                         if(&Network::check_subnet($network)) {
1275                                 # Add the generated network to the array of networks.
1276                                 push(@networks, $network);
1277                         }
1278                 }
1279         }
1280
1281         # Format home net declaration.
1282         my $line = "\"[" . join(',', @networks) . "]\"";
1283
1284         # Open file to store the addresses of the home net.
1285         open(FILE, ">$homenet_file") or die "Could not open $homenet_file. $!\n";
1286
1287         # Print yaml header.
1288         print FILE "%YAML 1.1\n";
1289         print FILE "---\n\n";
1290
1291         # Print notice about autogenerated file.
1292         print FILE "#Autogenerated file. Any custom changes will be overwritten!\n";
1293
1294         # Print the generated and required HOME_NET declaration to the file.
1295         print FILE "HOME_NET:\t$line\n";
1296
1297         # Close file handle.
1298         close(FILE);
1299 }
1300
1301 #
1302 # Function to generate and write the file which contains the configured and used DNS servers.
1303 #
1304 sub generate_dns_servers_file() {
1305         # Get the used DNS servers.
1306         my @nameservers = &General::get_nameservers();
1307
1308         # Get network settings.
1309         my %netsettings;
1310         &General::readhash("${General::swroot}/ethernet/settings", \%netsettings);
1311
1312         # Format dns servers declaration.
1313         my $line = "";
1314
1315         # Check if the system has configured nameservers.
1316         if (@nameservers) {
1317                 # Add the GREEN address as DNS servers.
1318                 push(@nameservers, $netsettings{'GREEN_ADDRESS'});
1319
1320                 # Check if a BLUE zone exists.
1321                 if ($netsettings{'BLUE_ADDRESS'}) {
1322                         # Add the BLUE address to the array of nameservers.
1323                         push(@nameservers, $netsettings{'BLUE_ADDRESS'});
1324                 }
1325
1326                 # Generate the line which will be written to the DNS servers file.
1327                 $line = join(",", @nameservers);
1328         } else {
1329                 # External net simply contains (any).
1330                 $line = "\$EXTERNAL_NET";
1331         }
1332
1333         # Open file to store the used DNS server addresses.
1334         open(FILE, ">$dns_servers_file") or die "Could not open $dns_servers_file. $!\n";
1335
1336         # Print yaml header.
1337         print FILE "%YAML 1.1\n";
1338         print FILE "---\n\n";
1339
1340         # Print notice about autogenerated file.
1341         print FILE "#Autogenerated file. Any custom changes will be overwritten!\n";
1342
1343         # Print the generated DNS declaration to the file.
1344         print FILE "DNS_SERVERS:\t\"[$line]\"\n";
1345
1346         # Close file handle.
1347         close(FILE);
1348 }
1349
1350 #
1351 # Function to generate and write the file which contains the HTTP_PORTS definition.
1352 #
1353 sub generate_http_ports_file() {
1354         my %proxysettings;
1355
1356         # Read-in proxy settings
1357         &General::readhash("${General::swroot}/proxy/advanced/settings", \%proxysettings);
1358
1359         # Check if the proxy is enabled.
1360         if (( -e "${General::swroot}/proxy/enable") || (-e "${General::swroot}/proxy/enable_blue")) {
1361                 # Add the proxy port to the array of HTTP ports.
1362                 push(@http_ports, $proxysettings{'PROXY_PORT'});
1363         }
1364
1365         # Check if the transparent mode of the proxy is enabled.
1366         if ((-e "${General::swroot}/proxy/transparent") || (-e "${General::swroot}/proxy/transparent_blue")) {
1367                 # Add the transparent proxy port to the array of HTTP ports.
1368                 push(@http_ports, $proxysettings{'TRANSPARENT_PORT'});
1369         }
1370
1371         # Format HTTP_PORTS declaration.
1372         my $line = "";
1373
1374         # Generate line which will be written to the http ports file.
1375         $line = join(",", @http_ports);
1376
1377         # Open file to store the HTTP_PORTS.
1378         open(FILE, ">$http_ports_file") or die "Could not open $http_ports_file. $!\n";
1379
1380         # Print yaml header.
1381         print FILE "%YAML 1.1\n";
1382         print FILE "---\n\n";
1383
1384         # Print notice about autogenerated file.
1385         print FILE "#Autogenerated file. Any custom changes will be overwritten!\n";
1386
1387         # Print the generated HTTP_PORTS declaration to the file.
1388         print FILE "HTTP_PORTS:\t\"[$line]\"\n";
1389
1390         # Close file handle.
1391         close(FILE);
1392 }
1393
1394 #
1395 ## Function to generate and write the file for used rulefiles file for a given provider.
1396 ##
1397 ## The function requires as first argument a provider handle, and as second an array with files.
1398 #
1399 sub write_used_provider_rulefiles_file($@) {
1400         my ($provider, @files) = @_;
1401
1402         # Get the path and file for the provider specific used rulefiles file.
1403         my $used_provider_rulesfile_file = &get_used_provider_rulesfile_file($provider);
1404
1405         # Open file for used rulefiles.
1406         open (FILE, ">", "$used_provider_rulesfile_file") or die "Could not write to $used_provider_rulesfile_file. $!\n";
1407
1408         # Write yaml header to the file.
1409         print FILE "%YAML 1.1\n";
1410         print FILE "---\n\n";
1411
1412         # Write header to file.
1413         print FILE "#Autogenerated file. Any custom changes will be overwritten!\n";
1414
1415         # Loop through the array of given files.
1416         foreach my $file (@files) {
1417                 # Check if the given filename exists and write it to the file of used rulefiles.
1418                 if(-f "$rulespath/$file") {
1419                         print FILE " - $file\n";
1420                 }
1421         }
1422
1423         # Close file after writing.
1424         close(FILE);
1425 }
1426
1427 #
1428 ## Function to write the main file for provider rulesfiles inclusions.
1429 ##
1430 ## This function requires an array of provider handles.
1431 #
1432 sub write_main_used_rulefiles_file (@) {
1433         my (@providers) = @_;
1434
1435         # Call function to write the static rulefiles file.
1436         &_write_default_rulefiles_file();
1437
1438         # Open file for used rulefils inclusion.
1439         open (FILE, ">", "$suricata_used_providers_file") or die "Could not write to $suricata_used_providers_file. $!\n";
1440
1441         # Write yaml header to the file.
1442         print FILE "%YAML 1.1\n";
1443         print FILE "---\n\n";
1444
1445         # Write header to file.
1446         print FILE "#Autogenerated file. Any custom changes will be overwritten!\n";
1447
1448         # Loop through the list of given providers.
1449         foreach my $provider (@providers) {
1450                 # Call function to get the providers used rulefiles file.
1451                 my $filename = &get_used_provider_rulesfile_file($provider);
1452
1453                 # Check if the file exists and write it into the used rulefiles file.
1454                 if (-f $filename) {
1455                         # Print the provider to the file.
1456                         print FILE "include\: $filename\n";
1457                 }
1458         }
1459
1460         # Close the filehandle after writing.
1461         close(FILE);
1462 }
1463
1464 sub _write_default_rulefiles_file () {
1465         # Get enabled application layer protocols.
1466         my @enabled_app_layer_protos = &get_suricata_enabled_app_layer_protos();
1467
1468         # Open file.
1469         open (FILE, ">", $suricata_default_rulefiles_file) or die "Could not write to $suricata_default_rulefiles_file. $!\n";
1470
1471         # Write yaml header to the file.
1472         print FILE "%YAML 1.1\n";
1473         print FILE "---\n\n";
1474
1475         # Write notice about autogenerated file.
1476         print FILE "#Autogenerated file. Any custom changes will be overwritten!\n";
1477
1478         # Loop through the array of static included rulesfiles.
1479         foreach my $file (@static_included_rulefiles) {
1480                 # Check if the file exists.
1481                 if (-f "$rulespath/$file") {
1482                         # Write the rulesfile name to the file.
1483                         print FILE " - $rulespath/$file\n";
1484                 }
1485         }
1486
1487         print FILE "\n#Default rules for used application layer protocols.\n";
1488         foreach my $enabled_app_layer_proto (@enabled_app_layer_protos) {
1489                 # Check if the current processed app layer proto needs to be translated
1490                 # into an application name.
1491                 if (exists($tr_app_layer_proto{$enabled_app_layer_proto})) {
1492                         # Obtain the translated application name for this protocol.
1493                         $enabled_app_layer_proto = $tr_app_layer_proto{$enabled_app_layer_proto};
1494                 }
1495
1496                 # Generate filename.
1497                 my $rulesfile = "$default_rulespath/$enabled_app_layer_proto\.rules";
1498
1499                 # Check if such a file exists.
1500                 if (-f "$rulesfile") {
1501                         # Write the rulesfile name to the file.
1502                         print FILE " - $rulesfile\n";
1503                 }
1504
1505                 # Generate filename with "events" in filename.
1506                 $rulesfile = "$default_rulespath/$enabled_app_layer_proto\-events.rules";
1507
1508                 # Check if this file exists.
1509                 if (-f "$rulesfile" ) {
1510                         # Write the rulesfile name to the file.
1511                         print FILE " - $rulesfile\n";
1512                 }
1513         }
1514
1515         # Close the file handle
1516         close(FILE);
1517 }
1518
1519 #
1520 ## Tiny function to generate the full path and name for the used_provider_rulesfile file of a given provider.
1521 #
1522 sub get_used_provider_rulesfile_file ($) {
1523         my ($provider) = @_;
1524
1525         my $filename = "$settingsdir/suricata\-$provider\-used\-rulefiles.yaml";
1526
1527         # Return the gernerated file.
1528         return $filename;
1529 }
1530
1531 #
1532 ## Function to generate and write the file for modify the ruleset.
1533 #
1534 sub write_modify_sids_file() {
1535         # Get configured settings.
1536         my %idssettings=();
1537         &General::readhash("$ids_settings_file", \%idssettings);
1538
1539         # Open modify sid's file for writing.
1540         open(FILE, ">$modify_sids_file") or die "Could not write to $modify_sids_file. $!\n";
1541
1542         # Write file header.
1543         print FILE "#Autogenerated file. Any custom changes will be overwritten!\n";
1544
1545         # Check if the traffic only should be monitored.
1546         unless($idssettings{'MONITOR_TRAFFIC_ONLY'} eq 'on') {
1547                 # Suricata is in IPS mode, which means that the rule actions have to be changed
1548                 # from 'alert' to 'drop', however not all rules should be changed.  Some rules
1549                 # exist purely to set a flowbit which is used to convey other information, such
1550                 # as a specific type of file being downloaded, to other rulewhich then check for
1551                 # malware in that file.  Rules which fall into the first category should stay as
1552                 # alert since not all flows of that type contain malware.
1553
1554                 # These types of rulesfiles contain meta-data which gives the action that should
1555                 # be used when in IPS mode.  Do the following:
1556                 #
1557                 # 1. Disable all rules and set the action to 'drop'
1558                 # 2. Set the action back to 'alert' if the rule contains 'flowbits:noalert;'
1559                 #    This should give rules not in the policy a reasonable default if the user
1560                 #    manually enables them.
1561                 # 3. Enable rules and set actions according to the meta-data strings.
1562
1563                 my $policy = 'balanced';  # Placeholder to allow policy to be changed.
1564
1565                         print FILE <<END;
1566 modifysid * "^#(?:alert|drop)(.+policy $policy-ips alert)" | "alert\${1}"
1567 modifysid * "^#(?:alert|drop)(.+policy $policy-ips drop)" | "drop\${1}"
1568 modifysid * "^(#?)(?:alert|drop)" | "\${1}drop"
1569 modifysid * "^(#?)drop(.+flowbits:noalert;)" | "\${1}alert\${2}"
1570 END
1571                 }
1572
1573         # Close file handle.
1574         close(FILE);
1575 }
1576
1577 #
1578 ## Function to get the ruleset date for a given provider.
1579 ##
1580 ## The function simply return the creation date in a human read-able format
1581 ## of the stored providers rulesfile.
1582 #
1583 sub get_ruleset_date($) {
1584         my ($provider) = @_;
1585         my $date;
1586         my $mtime;
1587
1588         # Load neccessary perl modules for file stat and to format the timestamp.
1589         use File::stat;
1590         use POSIX qw( strftime );
1591
1592         # Get the stored rulesfile for this provider.
1593         my $stored_rulesfile = &_get_dl_rulesfile($provider);
1594
1595         # Check if we got a file.
1596         if (-f $stored_rulesfile) {
1597                 # Call stat on the rulestarball.
1598                 my $stat = stat("$stored_rulesfile");
1599
1600                 # Get timestamp the file creation.
1601                 $mtime = $stat->mtime;
1602         }
1603
1604         # Check if the timestamp has not been grabbed.
1605         unless ($mtime) {
1606                 # Return N/A for Not available.
1607                 return "N/A";
1608         }
1609
1610         # Convert into human read-able format.
1611         $date = strftime('%Y-%m-%d %H:%M:%S', localtime($mtime));
1612
1613         # Return the date.
1614         return $date;
1615 }
1616
1617 #
1618 ## Function to gather the version of suricata.
1619 #
1620 sub get_suricata_version($) {
1621         my ($format) = @_;
1622
1623         # Execute piped suricata command and return the version information.
1624         open(SURICATA, "suricata -V |") or die "Couldn't execute program: $!";
1625
1626         # Grab and store the output of the piped program.
1627         my $version_string = <SURICATA>;
1628
1629         # Close pipe.
1630         close(SURICATA);
1631
1632         # Remove newlines.
1633         chomp($version_string);
1634
1635         # Grab the version from the version string.
1636         $version_string =~ /([0-9]+([.][0-9]+)+)/;
1637
1638         # Splitt the version into single chunks.
1639         my ($major_ver, $minor_ver, $patchlevel) = split(/\./, $1);
1640
1641         # Check and return the requested version sheme.
1642         if ($format eq "major") {
1643                 # Return the full version.
1644                 return "$major_ver";
1645         } elsif ($format eq "minor") {
1646                 # Return the major and minor part.
1647                 return "$major_ver.$minor_ver";
1648         } else {
1649                 # Return the full version string.
1650                 return "$major_ver.$minor_ver.$patchlevel";
1651         }
1652 }
1653
1654 #
1655 ## Function to get the enabled application layer protocols.
1656 #
1657 sub get_suricata_enabled_app_layer_protos() {
1658         # Array to store and return the enabled app layer protos.
1659         my @enabled_app_layer_protos = ();
1660
1661         # Execute piped suricata command and return the list of
1662         # enabled application layer protocols.
1663         open(SURICATA, "suricata --list-app-layer-protos |") or die "Could not execute program: $!";
1664
1665         # Grab and store the list of enabled application layer protocols.
1666         my @output = <SURICATA>;
1667
1668         # Close pipe.
1669         close(SURICATA);
1670
1671         # Merge allways enabled static application layers protocols array.
1672         @enabled_app_layer_protos = @static_enabled_app_layer_protos;
1673
1674         # Loop through the array which contains the output of suricata.
1675         foreach my $line (@output) {
1676                 # Skip header line which starts with "===".
1677                 next if ($line =~ /^\s*=/);
1678
1679                 # Skip info or warning lines.
1680                 next if ($line =~ /\s*--/);
1681
1682                 # Remove newlines.
1683                 chomp($line);
1684
1685                 # Add enabled app layer proto to the array.
1686                 push(@enabled_app_layer_protos, $line);
1687         }
1688
1689         # Sort the array.
1690         @enabled_app_layer_protos = sort(@enabled_app_layer_protos);
1691
1692         # Return the array.
1693         return @enabled_app_layer_protos;
1694 }
1695
1696 #
1697 ## Function to generate the rules file with whitelisted addresses.
1698 #
1699 sub generate_ignore_file() {
1700         my %ignored = ();
1701
1702         # SID range 1000000-1999999 Reserved for Local Use
1703         # Put your custom rules in this range to avoid conflicts
1704         my $sid = 1500000;
1705
1706         # Read-in ignoredfile.
1707         &General::readhasharray($IDS::ignored_file, \%ignored);
1708
1709         # Open ignorefile for writing.
1710         open(FILE, ">$IDS::whitelist_file") or die "Could not write to $IDS::whitelist_file. $!\n";
1711
1712         # Config file header.
1713         print FILE "# Autogenerated file.\n";
1714         print FILE "# All user modifications will be overwritten.\n\n";
1715
1716         # Add all user defined addresses to the whitelist.
1717         #
1718         # Check if the hash contains any elements.
1719         if (keys (%ignored)) {
1720                 # Loop through the entire hash and write the host/network
1721                 # and remark to the ignore file.
1722                 while ( (my $key) = each %ignored) {
1723                         my $address = $ignored{$key}[0];
1724                         my $remark = $ignored{$key}[1];
1725                         my $status = $ignored{$key}[2];
1726
1727                         # Check if the status of the entry is "enabled".
1728                         if ($status eq "enabled") {
1729                                 # Check if the address/network is valid.
1730                                 if ((&General::validip($address)) || (&General::validipandmask($address))) {
1731                                         # Write rule line to the file to pass any traffic from this IP
1732                                         print FILE "pass ip $address any -> any any (msg:\"pass all traffic from/to $address\"\; bypass; sid:$sid\;)\n";
1733
1734                                         # Increment sid.
1735                                         $sid++;
1736                                 }
1737                         }
1738                 }
1739         }
1740
1741         close(FILE);
1742 }
1743
1744 #
1745 ## Function to set correct ownership for single files and directories.
1746 #
1747
1748 sub set_ownership($) {
1749         my ($target) = @_;
1750
1751         # User and group of the WUI.
1752         my $uname = "nobody";
1753         my $grname = "nobody";
1754
1755         # The chown function implemented in perl requies the user and group as nummeric id's.
1756         my $uid = getpwnam($uname);
1757         my $gid = getgrnam($grname);
1758
1759         # Check if the given target exists.
1760         unless ($target) {
1761                 # Stop the script and print error message.
1762                 die "The $target does not exist. Cannot change the ownership!\n";
1763         }
1764
1765         # Check weather the target is a file or directory.
1766         if (-f $target) {
1767                 # Change ownership ot the single file.
1768                 chown($uid, $gid, "$target");
1769         } elsif (-d $target) {
1770                 # Do a directory listing.
1771                 opendir(DIR, $target) or die $!;
1772                         # Loop through the direcory.
1773                         while (my $file = readdir(DIR)) {
1774
1775                                 # We only want files.
1776                                 next unless (-f "$target/$file");
1777
1778                                 # Set correct ownership for the files.
1779                                 chown($uid, $gid, "$target/$file");
1780                         }
1781
1782                 closedir(DIR);
1783
1784                 # Change ownership of the directory.
1785                 chown($uid, $gid, "$target");
1786         }
1787 }
1788
1789 #
1790 ## Function to read-in the aliases file and returns all configured and enabled aliases.
1791 #
1792 sub get_aliases() {
1793         # Location of the aliases file.
1794         my $aliases_file = "${General::swroot}/ethernet/aliases";
1795
1796         # Array to store the aliases.
1797         my @aliases;
1798
1799         # Check if the file is empty.
1800         if (-z $aliases_file) {
1801                 # Abort nothing to do.
1802                 return;
1803         }
1804
1805         # Open the aliases file.
1806         open(ALIASES, $aliases_file) or die "Could not open $aliases_file. $!\n";
1807
1808         # Loop through the file content.
1809         while (my $line = <ALIASES>) {
1810                 # Remove newlines.
1811                 chomp($line);
1812
1813                 # Splitt line content into single chunks.
1814                 my ($address, $state, $remark) = split(/\,/, $line);
1815
1816                 # Check if the state of the current processed alias is "on".
1817                 if ($state eq "on") {
1818                         # Check if the address is valid.
1819                         if(&Network::check_ip_address($address)) {
1820                                 # Add the alias to the array of aliases.
1821                                 push(@aliases, $address);
1822                         }
1823                 }
1824         }
1825
1826         # Close file handle.
1827         close(ALIASES);
1828
1829         # Return the array.
1830         return @aliases;
1831 }
1832
1833 #
1834 ## Function to grab the current assigned IP-address on red.
1835 #
1836 sub get_red_address() {
1837         # File, which contains the current IP-address of the red interface.
1838         my $file = "${General::swroot}/red/local-ipaddress";
1839
1840         # Check if the file exists.
1841         if (-e $file) {
1842                 # Open the given file.
1843                 open(FILE, "$file") or die "Could not open $file.";
1844
1845                 # Obtain the address from the first line of the file.
1846                 my $address = <FILE>;
1847
1848                 # Close filehandle
1849                 close(FILE);
1850
1851                 # Remove newlines.
1852                 chomp $address;
1853
1854                 # Check if the grabbed address is valid.
1855                 if (&General::validip($address)) {
1856                         # Return the address.
1857                         return $address;
1858                 }
1859         }
1860
1861         # Return nothing.
1862         return;
1863 }
1864
1865 #
1866 ## Function to get the used rules files of a given provider.
1867 #
1868 sub read_used_provider_rulesfiles($) {
1869         my ($provider) = @_;
1870
1871         # Array to store the used rulefiles.
1872         my @used_rulesfiles = ();
1873
1874         # Get the used rulesefile file for the provider.
1875         my $rulesfile_file = &get_used_provider_rulesfile_file($provider);
1876
1877         # Check if the a used rulesfile exists for this provider.
1878         if (-f $rulesfile_file) {
1879                 # Open the file or used rulefiles and read-in content.
1880                 open(FILE, $rulesfile_file) or die "Could not open $rulesfile_file. $!\n";
1881
1882                 while (<FILE>) {
1883                         # Assign the current line to a nice variable.
1884                         my $line = $_;
1885
1886                         # Remove newlines.
1887                         chomp($line);
1888
1889                         # Skip comments.
1890                         next if ($line =~ /\#/);
1891
1892                         # Skip blank  lines.
1893                         next if ($line =~ /^\s*$/);
1894
1895                         # Gather the rulefile.
1896                         if ($line =~ /.*- (.*)/) {
1897                                 my $rulefile = $1;
1898
1899                                 # Add the rulefile to the array of used rulesfiles.
1900                                 push(@used_rulesfiles, $rulefile);
1901                         }
1902                 }
1903
1904                 # Close the file.
1905                 close(FILE);
1906         }
1907
1908         # Return the array of used rulesfiles.
1909         return @used_rulesfiles;
1910 }
1911
1912 #
1913 ## Function to write the lock file for locking the WUI, while
1914 ## the autoupdate script runs.
1915 #
1916 sub lock_ids_page() {
1917         # Call subfunction to create the file.
1918         &create_empty_file($ids_page_lock_file);
1919 }
1920
1921 #
1922 ## Function to release the lock of the WUI, again.
1923 #
1924 sub unlock_ids_page() {
1925         # Delete lock file.
1926         unlink($ids_page_lock_file);
1927 }
1928
1929 1;